From 5bde4e0b4a1b13f8aac3cb986556af55233e8e8f Mon Sep 17 00:00:00 2001
From: a1denvalu3 <cloudsupper@proton.me>
Date: Thu, 30 Jul 2026 14:29:22 +0200
Subject: [PATCH] Close fully visible geohash outlines

---
 .../com/bitchat/android/ui/globe/GlobeView.kt | 13 ++++++--
 .../android/ui/globe/GlobeGeometryTest.kt     | 31 +++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 app/src/test/kotlin/com/bitchat/android/ui/globe/GlobeGeometryTest.kt

diff --git a/app/src/main/java/com/bitchat/android/ui/globe/GlobeView.kt b/app/src/main/java/com/bitchat/android/ui/globe/GlobeView.kt
index e7717735..619973be 100644
--- a/app/src/main/java/com/bitchat/android/ui/globe/GlobeView.kt
+++ b/app/src/main/java/com/bitchat/android/ui/globe/GlobeView.kt
@@ -421,7 +421,7 @@ private fun DrawScope.drawGraticule(
     drawPath(path, color, style = Stroke(width = 1f))
 }
 
-private data class DiscPt(val x: Float, val y: Float, val front: Boolean)
+internal data class DiscPt(val x: Float, val y: Float, val front: Boolean)
 
 private fun limbPoint(behind: DiscPt, front: DiscPt): Pair<Float, Float> {
     var lo = 0f; var hi = 1f
@@ -440,7 +440,10 @@ private fun limbPoint(behind: DiscPt, front: DiscPt): Pair<Float, Float> {
  * padded with the horizon intersection point so they can be closed along the horizon.
  * Pass [closed] = false for open polylines (border lines).
  */
-private fun buildFrontRuns(pts: List<DiscPt>, closed: Boolean = true): List<MutableList<Pair<Float, Float>>> {
+internal fun buildFrontRuns(
+    pts: List<DiscPt>,
+    closed: Boolean = true
+): List<MutableList<Pair<Float, Float>>> {
     if (pts.isEmpty()) return emptyList()
     val n = pts.size
     val runs = mutableListOf<MutableList<Pair<Float, Float>>>()
@@ -477,6 +480,12 @@ private fun buildFrontRuns(pts: List<DiscPt>, closed: Boolean = true): List<Muta
         if (closed && runs.isNotEmpty() && pts[0].front && pts[n - 1].front) {
             runs[0] = (run + runs[0]).toMutableList()
         } else {
+            // A fully front-facing ring has no limb transition to terminate its run.
+            // Close it explicitly; cell boundary sampling intentionally omits the
+            // duplicated final corner.
+            if (closed && runs.isEmpty() && pts[0].front && pts[n - 1].front) {
+                run.add(run.first())
+            }
             runs.add(run)
         }
     }
diff --git a/app/src/test/kotlin/com/bitchat/android/ui/globe/GlobeGeometryTest.kt b/app/src/test/kotlin/com/bitchat/android/ui/globe/GlobeGeometryTest.kt
new file mode 100644
index 00000000..55f5311b
--- /dev/null
+++ b/app/src/test/kotlin/com/bitchat/android/ui/globe/GlobeGeometryTest.kt
@@ -0,0 +1,31 @@
+package com.bitchat.android.ui.globe
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Test
+
+class GlobeGeometryTest {
+
+    private val square = listOf(
+        DiscPt(-0.5f, -0.5f, front = true),
+        DiscPt(0.5f, -0.5f, front = true),
+        DiscPt(0.5f, 0.5f, front = true),
+        DiscPt(-0.5f, 0.5f, front = true)
+    )
+
+    @Test
+    fun closedFullyVisibleRing_connectsLastPointToFirst() {
+        val run = buildFrontRuns(square, closed = true).single()
+
+        assertEquals(square.size + 1, run.size)
+        assertEquals(run.first(), run.last())
+    }
+
+    @Test
+    fun openFullyVisibleLine_doesNotConnectLastPointToFirst() {
+        val run = buildFrontRuns(square, closed = false).single()
+
+        assertEquals(square.size, run.size)
+        assertNotEquals(run.first(), run.last())
+    }
+}